Henry VI of England (1421)

Henry VI became king of England when he was not yet nine months old. That same year, the English proclaimed the infant the successor to the French throne, but France did not recognize this. The young monarch grew up to be a mild, honest, and pious man, a patron of literature and the arts. He was, however, also mentally unstable, weak-willed, and politically naive, and this created a power vacuum that his overly powerful ministers vied to fill, eventually resulting in what decades-long conflict? Discuss

Source: The Free Dictionary